Device for stretching flexible members



June 10, 1947. A. c. ANSELMI DEVICE FOR STRETCHING FLEXIBLE MEMBERS Filed. April 20, 1944 2 Sheeis-Sheet l A. C. ANSELME DEVICE FOR STRETCHING FLEXIBLE MEMBERS 2 Sheets-Sheet 2 Filed April 20, 1944 E u fl fiT VQHHLWHT HHF IH U 2% LI 1 H Ti llllllllllllllllllll IILI A m lTLUciZZZQZ A. 0.122266 13ml Patented June 10, 1947 DEVICE FOR STRETCHING FLEXIBLE MEllIBE-RS Anthony Cesare Anselmi, Oxford, England, as-

signor to Hellermann Electric Limited, Oxford,

England Application April 20, 1944, Serial No. 531,976 In Great Britain December 29, 1943 1 Claim. 1

This invention relates to an improved device for stretching rubber and other flexible tubing for binding, insulating, marking and other purposes, the invention being more particularly intended for use in connection with electrical conductors but not being limited thereto.

The object of the present invention is to provide an improved stretching device of simple and robust construction and in which the tube stretching mechanism can be more conveniently and more rapidly operated than in the devices hitherto proposed.

According to the present invention, a plurality (three, four or more) of tube stretching pins are so mounted through two-arm levers on two relatively rotatable concentric rings at right angles to the plane of rotation that in the position in which they receive the tube to be stretched, the pins lie close together, and that during the stretching operation, the relative rotation between the rings through a predetermined angle causes the lever arms gradually to separate the stretching pins to the required extent parallel to each other.

The inner one of the two concentric rings is stationary and the outer one rotatably mounted thereon, the levers carrying the stretching pins at the free end of one of their arms, being pivoted on the inner fixed ring and in slot-and-pin engagement with the outer rotatable ring at the free end of their other arm. In the position for the reception of the flexible tubing to be stretched, all the levers are radial with respect to the two rings, the free ends of their inner arms abutting against each other and the stretching pins projecting from the latter arms lying close together in or near the axis of the rings. Upon the outer ring being rotated the levers are pivoted on the fixed ring, and their inner arms are separated from each other, whereby the pins also become separated and cause the flexible tubing to be stretched.

In order to strengthen the attachment of the stretching pins to the levers, the latter are cast around them as hereinafter more particularly referred to.

The whole of the device is mounted on a supporting bracket and the rotary ring is rocked through the required angle, preferably by means of a pedal operated Bowden cable, in one direction to separate the stretching pins and in the other direction to discontinue the stretching effort. Other suitable means may be used instead for rotatably rocking the operating ring.

One mode of carrying the invention into effect is illustrated, by way of example, in the accompanying drawings, in which- Figure 1 is a front elevation of the improved device adapted to be pedal operated by means of a Bowden cable;

Figure 2 is a side sectional elevation along the line A-A in Figure 1; T

Figure 3 is another front elevation showing the position assumed by the device when the flexible tubing is in its stretched condition;

Figures 4 and 5 are respectively a sectional elevation and a sectional plan of one of the levers provided with a stretching pin.

Referring to the drawings, a is a frame, intended to be attached to any suitable support; I) is a stationary ring secured to the frame and on which a ring 0 is loosely mounted so that it can be rocked thereon by a Bowden cable (1, one end of which is attached to the fixed support a through the interposition of a spring Z and its other end to a pedal. The ring 0 is provided with a peripheral groove e for the reception of the Bowden cable and also with an indentation j for engagement with an abutment g on the cable, to enable the ring 0 to be angularly displaced in the one and the other direction when the cable is operated by the pedal.

Pivoted on the bolts h, by which the stationary ring I) is secured to the frame a, are four levers i, the extreme end of the inner arm 2'1 of each of which has, projecting at right angles to itself and the ring b, a stretching pin 1', whilst the outer arm 12 is in pin-and-slot engagement with the rotatable ring 0, the latter being provided for this purpose with a corresponding number of slots k.

With a view to strengthening the attachment of the stretching pins 7', the levers i are cast, preferably die-cast, on them as shown in Figures 4 and 5. The pins are bent at right angles at 7'1 and i2, the part between the bends 7'1 and 1'2, including the bends, having the lever 1; die-cast thereon, the part 53 in front of 71, forming the actual stretching pin and the part '4 beyond 9'2 forming the pin engagement with the slot 70. The part between 1'1 and 7'2 is bent as shown at it in Figure 5 for the purpose of increasing the anchorage. The forward end 7'6 of the pin is filed to an edge, so that when all the pins are close to each other, as shown in Figure 1, the flexible tubing can easily he slipped thereon.

When the ring 0 is rotatably rocked by the Bowden cable in order to separate the pins and stretch the flexible tubing placed over them, the levers i are turned on their pivots h, being driven by the slot-and-pin engagement k, '4, until they close to each other as shown iniFigure; 1. The;- central hole b1 in the stationary ring b permits;

the conductor to be inserted within the stretched tubing to any desired extent'to al-lowthelatterto be placed on to the conductor at whatever required point.

For some kind of work, it may-be desirable-to, lock the device in its opened position. This :-may.-

be efiected by pressing the rotary ring a ainst the stationary ring b, such as by means of'a knob operated set screw m, thereby causing friction between the two rings,' which prevents relative rotation between them.

Thedetails forcarryingthe invention into efieot may bemodified withoutin anywaydeparting from the scope of, the invention.

' Iclaim:

A device for stretching fiexible members, comprising in, combination two relatively rotating members, atleast three levers interconnecting the latter, each carrying a tube stretching pin, all of'which pins project, at right angles to the plane of rotation of ;the said relatively rotating members and lying close together in'the position in which they; receive the tube to bestretched and means for relatively rotating the said rotating members, whereby the relative rotation of the latter causes the levers gradually to separate the stretching pins to the required extent parallel to each other and thereby stretch the tube, in which the-two relatively; rotating members consist of an innerstationary ring and an outer rotating ring mounted on and concentrically surrounding the stationary ring and the interconnectinglevers-being two-armed levers which are pivoted to the inner stationary ring and have secured therein a rod bent at two points at right angleathe part between the bends lying within the lever-and'the: part thereon in front of the one bend forming the actual stretching pin whilst the part lying; behind the other bend forms a pinwhich engages in a slot provided in the movablering,

ANTHONY CESARE ANSELMI.

REFERENCES. CITED The following references are of record, in the,

file of this patent:

UNITED STATES. PATENTS;

FOREIGN PATENTS Country Date Great Britain Apr; 11, 1939 Number 

